Abstract: Objective: To explore the correlation between high-sensitivity C reactivity protein (hs-CRP) and atrial fibrillation. Methods: Sixty-one patients with nonvalvular atrial fibrillation were divided into two groups:paroxysmal atrial fibrillation(PAF) group (30 cases) and subtained atrial fibrillation (SAF) and control group(the other 31 cases with sinus rhythm acted). The serum hs-CRP levels and the left atrial internal diameter of all the cases were measured by immunochemistry method and echocardiography. Results: The hs-CRP level of PAF group and SAF group was significantly higher than that of the control (P < 0.05 to P < 0.01); the serum hsCRP level and the left atrial internal diameter of SAF group were significantly higher than that of PAF group(P < 0.01),and the serum hs-CRP level was positively related with the left atrial internal diameter(P < 0.05). Conclusions: The level of serum hs-CRP increases significantly in patients with atrial fibrillation, which indicaates that the inflammatory reation may promote the occurrence and maintenance of atrial fibrillation.